Roller mill structure

Abstract

A roller mill structure which achieves uniform distribution of fine particles passed through a rotary classifier to fine particle exits disposed at four points when conveying as pulverized coal milled in the roller mill on the air current is provided. A roller mill structure is configured to discharge pulverized coal obtained by milling a raw coal, which is loaded in a mill body ( 11 ), from fine particle exits ( 14 ) formed on the top of the mill body so as to be quartered in the circumferential direction to the outside by air current conveyance. The roller mill structure includes a table which rotates in the mill body ( 11 ), three rollers for rotating on the table and milling the raw coal, and a rotary classifier ( 20 ) disposed upstream of the fine particle exits ( 14 ), wherein a movable vane ( 21 ) for partly narrowing the cross-sectional area of a flow channel is provided at a midpoint of the flow channel for fine particle current flowing into the interior of the rotary classifier ( 20 ), and proceeding toward the fine particle exits ( 14 ).

The invention claimed is: 
     
       1. A roller mill structure configured to discharge fine particles obtained by milling a material to be milled, which is loaded in a mill body, from a plurality of fine particle exits formed on the top of the mill body so as to be separated in the circumferential direction to the outside by air current conveyance, said roller mill structure comprising:
 a table configured to rotate inside the mill body; 
 a plurality of rollers configured to rotate on the table and mill the material to be milled; and 
 a rotary classifier disposed directly upstream of the plurality of fine particle exits, 
 wherein a plurality of rectifying devices for partly narrowing a cross-sectional area of a flow channel are provided inside the rotary classifier, at a midpoint of the flow channel for fine particle current flowing into the interior of the rotary classifier and proceeding toward the plurality of fine particle exits, 
 wherein each of the plurality of rectifying devices is rotated individually, and 
 wherein the plurality of rectifying devices are configured with a plurality of panel-shaped damper members which pivot about a revolving shaft extending in a vertical direction, supported on a side wall side of the rotary classifier, so as to adjust the cross-sectional area of the flow channel. 
 
     
     
       2. The roller mill structure according to  claim 1 , wherein the fine particle exits are circumferentially separated and positioned adjacent to one another on the roller mill structure, and the plurality of rectifying devices are arranged between the fine particle exits. 
     
     
       3. The roller mill structure  claim 2 , wherein the rollers are disposed in axial symmetry with respect to the fine particle exits. 
     
     
       4. The roller mill structure according to  claim 1 , wherein the rollers are disposed in axial symmetry with respect to the fine particle exits. 
     
     
       5. The roller mill structure  claim 1 , wherein each of the plurality of rectifying devices are configured to pivot in a range from a first position of a minimum flow channel cross-section which substantially matches a diameter line passing through an axial center position of the rotary classifier to a second position, having a maximum flow channel cross-section, rotated leftward by substantially 90 degrees about the revolving shaft.